U.S. Pat. No. 1,690,557 discloses a wet razor having a metallic handle. This handle has the shape of a cylindrical rod, and has raised parts on its surface. Such raised parts can be produced by applying a pattern of parallel lines. The raised parts then have a diamond-shaped base, and appear as small pyramids. The pattern depicted is applied uniformly over the entire gripping surface. Such a pattern is primarily suitable for metallic surfaces. However, when the handle is wet the grip adhesion is not optimal. Because the raised parts all have the same height, the fingers do not have as much hold, in particular as soon as a finger slides off.
DE 10 2004 052 681 A1 discloses a handle that is intended to be suitable for a large number of devices. This handle has so-called acupressure features that are adapted to fit the inner surface of the hand. This handle is therefore intended to be held in a very particular position. If the device is held differently, it is difficult to grasp. In fact, when held differently this device provides an even less secure and comfortable grip than a smooth handle. The advantage of proposing a particular way of holding the handle is therefore achieved at the cost of poor suitability of the handle for other ways of holding it.
EP 1 127 529 A1 discloses a vacuum cleaner having a handle segment. This handle segment is produced by the combination of a harder plastic material and a softer, more graspable plastic material. The softer plastic material protrudes past the hard plastic surface in the form of knobs. The knobs therefore provide a degree of security to the grasping hand. However, in an electrically operated device, grasping comfort is greatest when the vibrations that almost unavoidably occur due to the electrical operation of the device are transferred to the hand only to a limited extent. The disclosed surface made of hard plastic, which is much larger than the surface of the knobs, will however probably result in a significant transmission of vibration.
Therefore, the present invention seeks to improve the prior art and to provide an improved surface structure for a working device. This surface structure is intended to enable a secure grip while allowing different holding positions, while nonetheless providing an optimal holding position. In addition, this surface structure is intended to transmit vibrations of the working device only to a limited extent.